An emissions control system, or aftertreatment system, may be included in an exhaust system of an engine in order to reduce regulated emissions. In one example, the aftertreatment system may include an oxidation catalyst and a particulate filter. The oxidation catalyst may convert nitric oxide (NO) to nitrogen dioxide (NO2) which oxidizes particulate matter (e.g., soot) in the particulate filter, thereby facilitating passive regeneration of the particulate filter. Over time, the aftertreatment system may become contaminated by various chemical compounds such as fuel additives, lube oil additives, sulfur from the lube oil, sulfur from the fuel, and the like, decreasing the efficiency of the aftertreatment system. As such, conversion of NO to NO2 in the oxidation catalyst may be reduced resulting in a lower frequency of passive regeneration and an increased frequency of active regeneration. Further, during active regeneration, fuel may be injected and burned in the exhaust passage upstream of the particulate filter in order to drive the temperature of the particulate filter up to a temperature where the particulate matter will burn. As such, fuel consumption is increased, thereby decreasing fuel economy.